1. Field of the Invention
The invention concerns a process for production of veneered compressed parts, in which a carrier, at least one intermediate veneer and a cover sheet of veneer are glued together under the exercise of a pressure of more than 200 N/cm2 at a temperature of more than 120° C. in a mold press to form a veneer preform, wherein first the veneer cover sheet and in certain cases the intermediate veneer are dyed in an aqueous dye bath at an overpressure at a temperature of 105° C. to 115° C. and then dried, and wherein the veneer preform is lacquered or painted on its free surface.
2. Description of the Related Art
In the manufacture of veneered pressed parts of this type conventionally less valuable wood is covered with a cover sheet or veneer of fine wood. In order to be able to satisfy a high quality standard in the finished mold-press parts even in the case of relatively low veneer qualities, it is known (DE-C 4206021), that the covered veneer and in certain cases the intermediate veneer are thoroughly dyed batch-wise in an aqueous dye bath and subsequently dried, and that a cover sheet of veneer pretreated in this manner as well as the intermediate veneer are joined with each other in a mold press. In the known processes the dye bath additionally contains an aqueous soluble or dispersible binder resin completely activatable at temperatures above 115° C., with which the veneer is treated during the dying process. The treatment of the cover and the intermediate veneer with the binder agent has the task of fixing the dyes and anchoring them in the wood, of improving the color trueness and water resistance as well as reinforcing the wood. During the dying process and the subsequent storage the binder does not completely harden. The final hardening occurs only under the influence of heat and pressure in the course of the mold pressing.
In practice the known process have been associated with recurring difficulties in keeping the binder agent additive dispersed in the dye bath. Frequently precipitation occurs, which can primarily be traced back to thermal reactions in the employed binder agent. Further, it has until now been necessary to join the veneers to each other by the interposition of dry glue sheets, since the veneers, in particular the cover sheet of veneer in the case of a one-sided coating with a wet adhesive, bow or warp and deform upon the uptake of moisture.